Alighting-gear of aircraft



H. BOLAS.

ALIGHT-ING GEAR OF AIRCRAFT.

APPLICATION FILED IAN. 6,1921.

Patented Aug. 29 IZL raras 'can w iban n'.

HAROLD BLAS, OF CLIFTON,`BRISTOL, ENGLAND, ASSGNOB, TO GEORGE I PARNAALL, 0F PARK ROW, BRS'IOL, ENGLAND.

ALIGHTINGr-GEAR 0F AERCRALT.

nascere.,

Application filed January 6, 1921.

To zZZ whomz't may concern.'

Be it known that l, HAROLD BOLAS, a subject of the King of Great Britain, residingv at 7 Windsor rPerrace, Clifton, Bristol, England, have inventedv a new and useful Improvement in and Relating to the Alighting- Gear of Aircraft, for which I have filed application in Great Britain, No. 22514, dated aeroplane, such machines being provided with wheels for alighting on the land or on av ship or other solid surface, and with a float or floats for alighting on water.

Machines of the aforesaid character which are termed hydro-aeroplanes have thelanding wheels so mounted that while on the one hand they may be used when the machine is leaving or alighting on the ground they will not present any head resistance when the machine is in the air, or on the water. The landing -Wheels are so mounted upon or relative to the float that they can be withdrawn above the level of the bottom of the Hoat or lowered below that level as occasion arises.

The present invention comprises alighting gear for aircraft of a combined seaplane and aeroplane character, wherein the alighting wheels are adjustahly disposed relative to the float so that they can be raisedabove the bottom surface of the float the axles of the alighting wheels being pivotally mounted wit-hin the float and connected to shock absorbers, said shock absorbers in turn being pivotally connected to the means for adjusting the position of the wheels, the aforesaid alighting gear embodying novel features of construction as will be hereinafter described. This invention will now be described in conjunction with the accompanying drawing which represents al half elevation of the chassis of the aircraft and shows the preferred means of carrying the invention into effect. In the drawing the full line position indicates the position of the mechanism when the landing wheels are in their lowest position for alighting on solid surfaces, that is the lower section of the landing wheel is below the bottom of the ioat, the dotted .lineV position of the mechanism indicates the Specification of Letters Patent.

Patented Aug. 2, 192i.

Serial No. 435,434.

position assumed bythe landing wheels and their connected mechanism when the wheels are raised to their highest position to permit of the aircraft alighting on water.

This invention is illustrated and will now be described as applied to a combined seaplane and aeroplane of the single central float type, the bottom of the float being indicated by the line designa-ted l. The alighting wheels 2 are disposed on cach side of the Hoat and are mounted on separate axles 3 which are` hinged at their inner ends on pins 4 fixed within the float. The axles 3 have a guided motion within slots 5 formed in the sides of the float, each side of the slots being formed by bulkheads which divide the float more or less into two sepa-rate compartments. Shock absorbers 6 are introduced between the axles 3 and the traversable nuts which will be hereinafter referred to. the said shock absorbers comprisf ing broadly telescopic spring controlled `members of substantially known construction which will not require further description.

For thepurpose of raising t-he alighting wheels 2 above the l er surface 1 of the lfloat horizontally traversable nuts 7 are provided which are pivotally connected to the upper ends of the shock absorbers. the nuts v7 being traversed thwartwise along horizon- -it is desired to move the nuts T toward the center of the fioat for the purpose of raising the alighting wheels the diiculty arises of causing the bearing block Ga atthe upper end of the shock absorber 6 to clear the inclined lower face 10 of the inw'ale 1() with' which it is in contact. In order to overcome this difficulty side links 11 which substantially form bell crank levers are fulcrumed on the nut 7 by means of the pin 12. the arni 112l of the link 11 is pivotally connected at 13 to the upper end of the shock l now be described.

absorber 6 and the pin 14twhich spans across the top ends of the arms 1lb ofthe links ll is, when in the outer position as seen in tull lines in the drawings, in contact with the face 'of the .adjustable stop 15 which is mounted in the frame'otl the aircraft. T he links itl are also provided with a cross pin 16 which forms a positioning stop for the links in relation to the nut 7 as will be hereinafter described.

The manner in which the bearing block 6 pivotally connected to the inner member of the telescopic spring controlled shock absorber 6 is removed from Contact with the inclined lower face 10L of the inwale lO will Rotation is imparted to the screw 8 through the chain drive to the sprocket wheel 9, by this rotation ot the screw 8 the nut '7 is transv-ersed toward the center ot' the float. rlraversed with the l nut are the bell cranked links 11 which are Imounted thereon and fulcrumed on the pin l2. This inward movement of the. nut 7 and the links 1l draws the bearing block 6a inwardly and downwardly along the inclined lower face 10a of the inwale 10, in so doing the spring within vthe telescopicl shock abthe arles 3 and the shock absorber 6 the bellv cranked links ll move to and occupy the dotted line position seen 'at the left hand side of the drawing and the pin le moves away from the head of the stop l5, the remainder ot' the traverse of the nut 7 and of the links 1l taking place with thejparts in the position indicated by the dotted lines. It will be seen that this inward motion otl the nut 7 has resulted in the raising of the alighting wheels 2 about their pivot 4 the wheels being gradually vraised until they reach the dotted line position indicated in the drawing.

As soon as the block 6a is removed from contact with the inwale- 10 the weight of and dependent from the shock absorber 6 'is Einsame suilicient to turn the links Il to the position seen in dotted lines on the left hand side ot" the figure, the motion of the links being limited in this direction by means of the stop pin 1G which now contacts withthe face 7 of the` nut '7. On a return motion being applied tothe screw 8 the pin la will be brought into contact with the adjustable stop l5 and continued motion of the screw 8 will rock the links il about their ulcrum l2 to position and maintain the bearing block 6 relative to the inwale 10 as seen by the right hand position in the drawing.

By means of this inventionthe alighting wheels can be positioned below7V the float or floats in the event of requiring to land the machine on a solidv surface, and when it may be desired to alight on or fly off the. water' the said wheels can be raised above the bottom surface of the float so as not to impede or interfere with the planing action of the machine. A

Claims l. Alighting gear for aircraft of ai combined seaplane and aeroplane character, comprising in combination Ia float, two alighting wheels mounted on separate axles,

said axles being pivotally mounted within said iioat, shock absorbing struts 'pivotally connected to said axle, means mounted on and controlled by a rotatable screw and pivotally connected to the upper end of said struts for simultaneously adjusting the position of the alighting wheels relative to the float.

2. Alighting gear foreircraft of a combined seaplane and aeroplane character, comprising in combination alighting wheels mounted on axles pivotally mounted at their inner ends, shock absorbing struts pivotally connected to said axles, said struts being pivotally connected at their upper end to blocks adapted to normally contact with the inwale of the aircraft, a rotatable screw, a i I traversable nut mounted thereon, links pivotally mounted on said nut, said'links being pivotally connected to said shock absorbing` struts and havingth'eir motion limited by stops. Y

In testimony whereof, l have signed my name to Ithis specification.

HAROLD BOLAS. 

